package LC;

/**
 * https://leetcode.com/problems/house-robber-ii/description/
 * Note: This is an extension of House Robber.
 * After robbing those houses on that street, the thief has found himself a new place for his thievery
 * so that he will not get too much attention.
 * This time, all houses at this place are arranged in a circle. That means the first house is the neighbor of the last one.
 * Meanwhile, the security system for these houses remain the same as for those in the previous street.
 * Given a list of non-negative integers representing the amount of money of each house,
 * determine the maximum amount of money you can rob tonight without alerting the police.
 * Credits:
 * Special thanks to @Freezen for adding this problem and creating all test cases.
 */
public class LC_213_HouseRobberII_Recur_Greedy {
    public static void main(String[] args) {
        System.out.println(Solution.rob(new int[]{1, 5, 3, 6, 2, 8, 1}));
    }

    static class Solution {
        static int rob(int[] nums) {
            if (nums == null || nums.length == 0) return 0;
            if (nums.length == 1) return nums[0];
            if (nums.length == 2) return Math.max(nums[0], nums[1]);
            return Math.max(robsub(nums, 0, nums.length - 2), robsub(nums, 1, nums.length - 1));
        }

        static int robsub(int[] nums, int s, int e) {
            int n = e - s + 1;
            int[] d = new int[n];
            d[0] = nums[s];
            d[1] = Math.max(nums[s], nums[s + 1]);

            for (int i = 2; i < n; i++) d[i] = Math.max(d[i - 2] + nums[s + i], d[i - 1]);
            return d[n - 1];
        }
    }
}